During the first 72 hours following surgery, the following information will be recorded: intensity of pain, opioid intake, side-effects attributable to analgesia and patient's level of satisfaction towards pain management. The occurence of pulmonary complications will be noted. Lung function will be measured using a peak flow meter. Length of stay in the recovery room, in the intermediate intensive care unit and in the hospital will be recorded. Time to reach post-anesthesia discharge criteria will be recorded.